How do I get the YouTube video ID from a URL?

Question

I want to get the v=id from YouTube’s URL with JavaScript (no jQuery, pure JavaScript).

Example YouTube URL formats

http://www.youtube.c

Answer 1

A slightly changed version from the one mantish posted:

var regExp = /^.*(youtu.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]{11,11}).*/;
var match = url.match(regExp);
if (match) if (match.length >= 2) return match[2];
// error

This assumes the code is always 11 characters. I'm using this in ActionScript, not sure if {11,11} is supported in Javascript. Also added support for &v=.... (just in case)